Although today the very idea of a science of law—the thought that law could be made a science like any other taught and studied at a modern university—has the ring of an oxymoron, this piece argues that the rejection of legal science was not only overhasty but unnecessary. There is a sense in which we can see law as a science, it argues, but only once we come to see more clearly and accurately just why the tradition of legal science begun in the earliest days of the Western legal tradition and brought to America by Christopher Columbus Langdell was destined to fail. The article accordingly lays out a reconstruction of both the basic idea of legal science and the specific conception that Langdell was effectively working out in the context of the American common law: the rationalist tradition of legal science. It contends that what was distinctive of the tradition was the absolutist way it had understood and framed the intellectual core of the law: its absolutism as to the law’s content, method, and viewpoint. After tracing that tradition from its twelfth-century origins through Langdell’s modern reinterpretation, the article goes on to examine the twofold critique of that science conceptualized by Holmes and later carried out in detail by the American Legal Realists, showing that, contrary to the claims of a rationalist legal science, the law is indeterminate not just in practice but in principle. Understanding this principled indeterminacy thus sets the stage for reconsideration of the failure of rationalist legal science, clearing the way for a pragmatic science of law, freed of absolutes.